Commit da834796 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86/asm changes from Ingo Molnar:
 "The one change that stands out is the alternatives patching change
  that prevents us from ever patching back instructions from SMP to UP:
  this simplifies things and speeds up CPU hotplug.

  Other than that it's smaller fixes, cleanups and improvements."

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Unspaghettize do_trap()
  x86_64: Work around old GAS bug
  x86: Use REP BSF unconditionally
  x86: Prefer TZCNT over BFS
  x86/64: Adjust types of temporaries used by ffs()/fls()/fls64()
  x86: Drop unnecessary kernel_eflags variable on 64-bit
  x86/smp: Don't ever patch back to UP if we unplug cpus
parents 80749df4 c416ddf5

Documentation/kernel-parameters.txt

+0 −3
Original line number Diff line number Diff line
@@ -2649,9 +2649,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
	smart2=		[HW]

			Format: <io1>[,<io2>[,...,<io8>]]



	smp-alt-once	[X86-32,SMP] On a hotplug CPU system, only

			attempt to substitute SMP alternatives once at boot.



	smsc-ircc2.nopnp	[HW] Don't use PNP to discover SMC devices

	smsc-ircc2.ircc_cfg=	[HW] Device configuration I/O port

	smsc-ircc2.ircc_sir=	[HW] SIR base I/O port

arch/x86/include/asm/alternative.h

+2 −2
Original line number Diff line number Diff line
@@ -60,7 +60,7 @@ extern void alternatives_smp_module_add(struct module *mod, char *name, 
					void *locks, void *locks_end,

					void *text, void *text_end);

extern void alternatives_smp_module_del(struct module *mod);

extern void alternatives_smp_switch(int smp);

extern void alternatives_enable_smp(void);

extern int alternatives_text_reserved(void *start, void *end);

extern bool skip_smp_alternatives;

#else
@@ -68,7 +68,7 @@ static inline void alternatives_smp_module_add(struct module *mod, char *name, 
					       void *locks, void *locks_end,

					       void *text, void *text_end) {}

static inline void alternatives_smp_module_del(struct module *mod) {}

static inline void alternatives_smp_switch(int smp) {}

static inline void alternatives_enable_smp(void) {}

static inline int alternatives_text_reserved(void *start, void *end)

{

	return 0;

arch/x86/include/asm/bitops.h

+6 −8
Original line number Diff line number Diff line
@@ -355,7 +355,7 @@ static int test_bit(int nr, const volatile unsigned long *addr); 
 */

static inline unsigned long __ffs(unsigned long word)

{

	asm("bsf %1,%0"

	asm("rep; bsf %1,%0"

		: "=r" (word)

		: "rm" (word));

	return word;
@@ -369,7 +369,7 @@ static inline unsigned long __ffs(unsigned long word) 
 */

static inline unsigned long ffz(unsigned long word)

{

	asm("bsf %1,%0"

	asm("rep; bsf %1,%0"

		: "=r" (word)

		: "r" (~word));

	return word;
@@ -417,10 +417,9 @@ static inline int ffs(int x) 
	 * We cannot do this on 32 bits because at the very least some

	 * 486 CPUs did not behave this way.

	 */

	long tmp = -1;

	asm("bsfl %1,%0"

	    : "=r" (r)

	    : "rm" (x), "0" (tmp));

	    : "rm" (x), "0" (-1));

#elif defined(CONFIG_X86_CMOV)

	asm("bsfl %1,%0\n\t"

	    "cmovzl %2,%0"
@@ -459,10 +458,9 @@ static inline int fls(int x) 
	 * We cannot do this on 32 bits because at the very least some

	 * 486 CPUs did not behave this way.

	 */

	long tmp = -1;

	asm("bsrl %1,%0"

	    : "=r" (r)

	    : "rm" (x), "0" (tmp));

	    : "rm" (x), "0" (-1));

#elif defined(CONFIG_X86_CMOV)

	asm("bsrl %1,%0\n\t"

	    "cmovzl %2,%0"
@@ -490,13 +488,13 @@ static inline int fls(int x) 
#ifdef CONFIG_X86_64

static __always_inline int fls64(__u64 x)

{

	long bitpos = -1;

	int bitpos = -1;

	/*

	 * AMD64 says BSRQ won't clobber the dest reg if x==0; Intel64 says the

	 * dest reg is undefined if x==0, but their CPU architect says its

	 * value is written to set it to the same as before.

	 */

	asm("bsrq %1,%0"

	asm("bsrq %1,%q0"

	    : "+r" (bitpos)

	    : "rm" (x));

	return bitpos + 1;

arch/x86/include/asm/calling.h

+23 −25
Original line number Diff line number Diff line
@@ -49,38 +49,36 @@ For 32-bit we have the following conventions - kernel is built with 
#include "dwarf2.h"



/*

 * 64-bit system call stack frame layout defines and helpers, for

 * assembly code (note that the seemingly unnecessary parentheses

 * are to prevent cpp from inserting spaces in expressions that get

 * passed to macros):

 * 64-bit system call stack frame layout defines and helpers,

 * for assembly code:

 */



#define R15		  (0)

#define R14		  (8)

#define R13		 (16)

#define R12		 (24)

#define RBP		 (32)

#define RBX		 (40)

#define R15		  0

#define R14		  8

#define R13		 16

#define R12		 24

#define RBP		 32

#define RBX		 40



/* arguments: interrupts/non tracing syscalls only save up to here: */

#define R11		 (48)

#define R10		 (56)

#define R9		 (64)

#define R8		 (72)

#define RAX		 (80)

#define RCX		 (88)

#define RDX		 (96)

#define RSI		(104)

#define RDI		(112)

#define ORIG_RAX	(120)       /* + error_code */

#define R11		 48

#define R10		 56

#define R9		 64

#define R8		 72

#define RAX		 80

#define RCX		 88

#define RDX		 96

#define RSI		104

#define RDI		112

#define ORIG_RAX	120       /* + error_code */

/* end of arguments */



/* cpu exception frame or undefined in case of fast syscall: */

#define RIP		(128)

#define CS		(136)

#define EFLAGS		(144)

#define RSP		(152)

#define SS		(160)

#define RIP		128

#define CS		136

#define EFLAGS		144

#define RSP		152

#define SS		160



#define ARGOFFSET	R11

#define SWFRAME		ORIG_RAX

arch/x86/include/asm/processor.h

+0 −1
Original line number Diff line number Diff line
@@ -423,7 +423,6 @@ DECLARE_INIT_PER_CPU(irq_stack_union); 


DECLARE_PER_CPU(char *, irq_stack_ptr);

DECLARE_PER_CPU(unsigned int, irq_count);

extern unsigned long kernel_eflags;

extern asmlinkage void ignore_sysret(void);

#else	/* X86_64 */

#ifdef CONFIG_CC_STACKPROTECTOR

CRA Git | Maintained and supported by SUSTech CRA and CCSE